1. Technical Field
This disclosure relates to circuit breakers, and more particularly, to a circuit breaker having a moisture resistant push to test button.
2. Description of the Related Art
Circuit breakers with ground fault or arc fault systems typically include a self-test button. These button designs usually include a mechanical spring, a secondary contact, and a hard plastic Push to Test (PTT) button. The test button is typically biased by a mechanical force provided by the spring. As the test button is depressed, the mechanical spring makes contact with a secondary contact. The secondary contact can be made of a similar material as the mechanical spring and may have spring type properties, or the secondary contact may be a stationary pin mounted on a printed circuit board (PCB).
One disadvantage is that a gap between the test button and a housing of the circuit breaker is present before or during when the button is depressed. When the gap between the button and the housing is present, several concerns arise related to moisture, corrosion, and potential electric shock. With the gap present, internal components are exposed to outside moisture and/or other containments that could disable the tripping functions of the test button. Although PCB's are typically conformally coated, this does not guarantee that moisture could not damage the PCB and/or related electrical components and disable the push to test button.
From a manufacturing standpoint, special care needs to be taken to ensure the contacting surfaces are not subject to corrosion or water damage. Current designs may be subject to corrosion on the contact surfaces if the mechanical parts were not properly coated, thus, disabling the push to test button functions. Further, the possibility of the user being exposed to electrical shock may be present.